Asymmetric and time-varying error-correction: an application to labour demand in the UK

In this paper we compare the asymmetric and time-varying error-correction models that have recently been proposed, and apply these to the case of UK aggregate labour demand. The aim of the paper is to investigate the possible co-existence of time-varying adjustment on the one hand, and constant asymmetric error-correction on the other hand. We find that without allowing for time-varying adjustment variables, the asymmetric error-correction models of Granger and Lee (1989) and Escribano (1986) work well. But once the time-varying adjustment variables are included, the evidence for time-invariant asymmetric adjustment is marginal

Anomalous enhancement of a penguin hadronic matrix element in B->K eta'

We estimate the density matrix element for the pi^0, eta and eta' production from the vacuum in the large-N_c limit. As a consequence, we find that the QCD axial anomaly leads to highly non-trivial corrections to the usual flavour SU(3) relations between B^0-> K^0 pi^0, B^0-> K^0 eta and B^0-> K^0 eta' decay amplitudes. These corrections may explain why the B-> K eta' branching ratio is about six times larger than the B-> K pi one.Comment: 5 pages, 1 figur

Differential Scanning Calorimetry (DSC) Analyses Of Superelastic And Nonsuperelastic Nickel-Titanium Orthodontic Wires

The purpose of this study was to determine the transformation temperatures for the austenitic, martensitic, and rhombohedral (R) structure phases in representative as-received commercial nitinol (NiTi) orthodontic wire alloys, to reconcile discrepancies among recent publications. Specimens were examined by differential scanning calorimetry (DSC) over a temperature range from approximately −170° C to 100° C, with a scanning rate of 10° C per minute. Two different pathways, with the intermediate R structure either absent or present, were observed for the transformation from martensitic to austenitic NiTi, whereas the reverse transformation from austenitic to martensitic NiTi always included the R structure. The enthalpy (ΔH) for the transformation from martensite to austenite ranged from 0.3 to 35 calories per gram. The lowest ΔH value for the nonsuperelastic Nitinol wire is consistent with a largely work-hardened, stable, martensitic microstructure in this product. The DSC results indicate that the transformation processes are broadly similar in superelastic, body-temperature shape-memory, and nonsuperelastic NiTi wires. Differences in bending properties for the NiTi orthodontic wires at room temperature and 37° C are due to the relative proportions of the metallurgical phases in the microstructures

Geometric phases in astigmatic optical modes of arbitrary order

The transverse spatial structure of a paraxial beam of light is fully characterized by a set of parameters that vary only slowly under free propagation. They specify bosonic ladder operators that connect modes of different order, in analogy to the ladder operators connecting harmonic-oscillator wave functions. The parameter spaces underlying sets of higher-order modes are isomorphic to the parameter space of the ladder operators. We study the geometry of this space and the geometric phase that arises from it. This phase constitutes the ultimate generalization of the Gouy phase in paraxial wave optics. It reduces to the ordinary Gouy phase and the geometric phase of non-astigmatic optical modes with orbital angular momentum states in limiting cases. We briefly discuss the well-known analogy between geometric phases and the Aharonov-Bohm effect, which provides some complementary insights in the geometric nature and origin of the generalized Gouy phase shift. Our method also applies to the quantum-mechanical description of wave packets. It allows for obtaining complete sets of normalized solutions of the Schr\"odinger equation. Cyclic transformations of such wave packets give rise to a phase shift, which has a geometric interpretation in terms of the other degrees of freedom involved.Comment: final versio

Public hospital costs and quality in the Dominican Republic

Measuring costs in public hospitals in developing countries is hampered by the lack of an appropriate costing system, or of any systematic cost accounting. Invoices for goods and services, prices for inputs, and patient records are generally absent. As a result, cost measures have historically been based on budget figures - the only available financial data. But budget allocations bear little relationship to the resources actually required to provide services to hospital patients. The patient-based methodology described by the authors circumvents this problem by measuring actual hospital resources allocated to patients. Their study was conducted in a single Dominican hospital during a one week period in April 1989. Their approach documents and gives prices for goods, services, and personnel time provided by the hospital to emergency patients, inpatients, and outpatients. They used the following to measure quality and efficiency: (a) the qualifications and relative costs of medical manpower delivering services; (b) the extent and nature of shortages; (c) comparisons of physician orders and actual services provided; and (d) (for selected diagnoses) the specifics of clinical practices in the hospital, compared with accepted clinical norms for the Dominican Republic. They found that average and total costs of services understate the true costs - because of shortages, inappropriate and underused personnel, and nonfunctioning equipment. Quality of care measures suggest low quality and poor efficiency. Norms of medical practice were not followed in more than 80 percent of the cases examined. Rates of completion for diagnostic tests were below 50 percent for outpatient services and between 60 and 70 percent for inpatient and emergency services. The study registered significant monthly savings of $641 for noncompletion of tests and$824 for nonavailability of drugs. Policy recommendations of the authors center on the need to reform the organization and delivery of health care as well as physician payment practices - and to giving more authority to hospital administrators. To make Dominican hospitals more efficient, there must be greater authority and accountability for hospital directors and better incentives for improving medical and management performance. Quality assurance needs great improvement if the Dominican system is to ensure a basic standard of care.Health Monitoring&Evaluation,Health Systems Development&Reform,Business Environment,Business in Development,Health Economics&Finance